3.4 Publication distribution by country and collaborations among countries
Scientific production at the global level is presented in Figure 4, where it becomes evident that industrialized countries were the most productive countries in terms of research outputs. A total of 50 countries published research in AMR in wildlife over the last 40 years. Of these, five countries contributed to approximately 72% of research publications total. The leadership of the United States, as well as the concentration of research in European countries, especially Spain, Portugal, United Kingdom and Sweden, stand out. In addition, Czech Republic and Italy in Europe, are prominent, as well as Canada and Australia. These results are not surprising and the dominance of these countries is probably related to their economic development and substantial amount of financial support to researchers, which has already been linked to overall academic output (Peng et al., 2019). The dominance of Portugal, Spain and Sweden is likely related to some prolific authors developing their interest. Figure 4 show regions that are poorly surveyed and where intensified sampling efforts could be most valuable, namely Asia, Africa and South America. A special focus has to be devoted to these countries as human populations are growing and landscapes are being transformed rapidly. Klein et al. (2018) showed that overall antibiotic consumption between 2000 and 2015 has increased by 65%, and in developing countries it has been meeting, or even exceeding, the levels observed in developed countries. Additionally, Van Boeckel et al. (2019) mapped resistance in livestock, showing that the largest hotspots of AMR in these animals are in China and India, with emerging countries such as Brazil and Kenya, all countries where research in AMR in wildlife has been residual or absent. The increase in meat production and demand, and the shift in livestock production systems in developing countries, stresses the importance to implement actions to prevent further aggravation of the AMR problem. This can be done by increasing collaborative research within this topic with countries where the laboratory and analytical infrastructures are already implemented but also by increased funding availability to increased infrastructures and qualified researchers in these countries, which will obviously translate into an increase in publications.
Interestingly, U.S.A. was also the country with a higher number of citations (total citations 1211), however it was the Czech Republic which scored the highest in the average article citation (39) (Table 2). It is important to stress that the number of citations is not a straightforward indicator of a paper quality but rather a measure of its impact among peers and/or visibility.
Two countries stand out with intense cooperation among themselves: Portugal and Spain in the Iberian Peninsula. This region has several scientific and technological activities which aim to intensify and consolidate strong scientific collaboration, apart from the cultural and language link (Knobel et al., 2013). Additionally, among the top 5 of the most productive authors, four are from the Iberian Peninsula (Table 2). Consistent with observations in other research fields, a small group of prolific authors contributed to a significant share of publications. For example, the top 5 authors, produced 41% of the total publications. Considering the number of publications the most productive authors in AMR research in wildlife were P. Poeta with 22 publications (10%), followed by C. Torres with 20 papers (9%), G. Igrejas 18 (8%), B. Olsen with 14 (7%), and A. Gonçalves with 13 (6%).
Spain, Germany, Sweden and France maintained active collaborations (Figure 4). The overview of publications that include international collaboration is a good indicator that research in this topic is becoming more internationally connected, a fact that can be observed in the map of global collaboration. Furthermore, international collaboration also demonstrates the importance of large collaborative networks to tackle AMR in wildlife, where ecological factors (e.g. , migratory behavior) contribute to the dissemination of resistance genes (Wellington et al., 2013). Overall, such information is valuable to discover new places where new work should start or where to build up some collaborations.